FREE REPAIR MANUALS & LABOR GUIDES 1982-2013 Vehicles
Courtesy of Operation CHARM: Car repair manuals for everyone.

Air/Fuel Mixture: Testing and Inspection

INSPECT CO/HC

HINT: The ECM properly controls the CO/HC concentration in the emission gas.

a. Start the engine.
b. Run the engine at 2,500 rpm for approximately 180 seconds.
c. Insert the CO/HC meter testing probe at least 40 cm (1.3 ft) into the tailpipe while idling.
d. Check the CO/HC concentration while idling and/or at 2,500 rpm.





If the CO/HC concentration does not comply with the regulations, troubleshoot in the order given.
- Check the heated oxygen sensor operation.
- See the table for possible causes, then inspect the applicable parts and repair them if necessary.